//这部分代码都是用来实现点击出现爱心的特效的
(function (window, document, undefined) {
    var hearts = [];
    window.requestAnimationFrame = (function(){
            return window.requestAnimationFrame || 
                       window.webkitRequestAnimationFrame ||
                       window.mozRequestAnimationFrame ||
                       window.oRequestAnimationFrame ||
                       window.msRequestAnimationFrame ||
                       function (callback){
                               setTimeout(callback,1000/60);
                       }
    })();
    init();
    function init(){
            css(".heart{width: 10px;height: 10px;position: fixed;background: #f00;transform: rotate(45deg);-webkit-transform: rotate(45deg);-moz-transform: rotate(45deg);}.heart:after,.heart:before{content: '';width: inherit;height: inherit;background: inherit;border-radius: 50%;-webkit-border-radius: 50%;-moz-border-radius: 50%;position: absolute;}.heart:after{top: -5px;}.heart:before{left: -5px;}");
            attachEvent();
            gameloop();
    }
    function gameloop(){
            for(var i=0;i<hearts.length;i++){
                if(hearts[i].alpha <=0){
                        document.body.removeChild(hearts[i].el);
                        hearts.splice(i,1);
                        continue;
                }
                hearts[i].y--;
                hearts[i].scale += 0.004;
                hearts[i].alpha -= 0.013;
                hearts[i].el.style.cssText = "left:"+hearts[i].x+"px;top:"+hearts[i].y+"px;opacity:"+hearts[i].alpha+";transform:scale("+hearts[i].scale+","+hearts[i].scale+") rotate(45deg);background:"+hearts[i].color;
        }
        requestAnimationFrame(gameloop);
    }
    function attachEvent(){
            var old = typeof window.onclick==="function" && window.onclick;
            window.onclick = function(event){
                    old && old();
                    createHeart(event);
            }
    }
    function createHeart(event){
        var d = document.createElement("div");
        d.className = "heart";
        hearts.push({
                el : d,
                x : event.clientX - 5,
                y : event.clientY - 5,
                scale : 1,
                alpha : 1,
                color : randomColor()
        });
        document.body.appendChild(d);
}
function css(css){
        var style = document.createElement("style");
            style.type="text/css";
            try{
                style.appendChild(document.createTextNode(css));
            }catch(ex){
                style.styleSheet.cssText = css;
            }
            document.getElementsByTagName('head')[0].appendChild(style);
}
    function randomColor(){
            return "rgb("+(~~(Math.random()*255))+","+(~~(Math.random()*255))+","+(~~(Math.random()*255))+")";
    }
})(window,document);